1. Field of the Invention
The present invention relates to orthopaedic implants, and, more particularly, to orthopaedic bodies which are inserted into an opening in a bone during orthopaedic surgery.
2. Description of the Related Art
An orthopaedic implant is typically implanted into an end of a bone, such as the proximal end of a femur. Occasionally, the bone includes an opening which is larger than necessary to receive the orthopaedic implant. For example, an end of a bone which is to receive a revision implant during a revision orthopaedic surgery may include an opening which is larger than the new revision implant which is to be implanted. As another example, a bone may include an opening which is larger than an implant as a result of a disease condition such as cancer. It is occasionally thus necessary to fill an enlarged opening in a bone to a desired extent to form a "neo-medullary" canal of appropriate size and shape to receive an implant.
A known method of filling an opening in a bone is to impact bone chips into the intramedullary (IM) canal to partially fill the IM canal. Such bone chips are commonly obtained from similar bones retrieved from donor cadavers. Such bone chips are known as "allograft" bone chips since they are obtained from cadavers. The bones are normally kept in a frozen state within a hospital and the surgeon grinds up the bones immediately prior to surgery. The bone chips are then poured into the opening in the bone and impacted in the opening using successively smaller tamps until a neo-medullary canal of proper size and shape is formed. A layer of bone cement is injected into the neo-medullary canal and the implant is cemented into the bone.
A problem with using allograft bone chips as described above is that the effectiveness of the technique is in large part dependent upon the skill of the surgeon. The size and shape of the bone particles may vary dependent upon how the bone particles are formed. Additionally, the type of tamp and force used during the tamping affects the impaction of the bone particles within the opening in the bone.
What is needed in the art is a surgical technique which allows a surgeon to more easily use an impaction allograft technique, and which reduces variability associated with presently uncontrolled parameters.